package com.example.myapplication;
import androidx.annotation.NonNull;
import androidx.appcompat.app.AppCompatActivity;
import android.content.ContentValues;
import android.content.Context;
import android.content.Intent;
import android.database.Cursor;
import android.database.sqlite.SQLiteDatabase;
import android.os.Bundle;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.ArrayAdapter;
import android.widget.BaseAdapter;
import android.widget.Button;
import android.widget.EditText;
import android.widget.ListView;
import android.widget.TextView;
import android.widget.Toast;
import java.util.ArrayList;
import java.util.List;
public class MainActivity extends AppCompatActivity implements View.OnClickListener {
Intent intent = new Intent();
EditText name,price,number;
Button add;
ListView lv;
private MyHelper helper;
List<Sqldata> list = new ArrayList<>();
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
name = (EditText)findViewById(R.id.et_1);
price = (EditText)findViewById(R.id.et_2);
number = (EditText)findViewById(R.id.et_3);
add = (Button)findViewById(R.id.add);
lv = (ListView)findViewById(R.id.list);
helper = new MyHelper(this);
}
public void add_Click(View view){
Sqldata date = new Sqldata(name.getText().toString(),price.getText().toString(),number.getText().toString());
insert(date);
Toast.makeText(MainActivity.this,name.getText().toString()+"已添加到购物车",Toast.LENGTH_SHORT).show();
}
public void delete_Click(View view){
int num = delete(name.getText().toString());
if (num > 0){
Toast.makeText(MainActivity.this,"删除成功",Toast.LENGTH_SHORT).show();
}else{
Toast.makeText(MainActivity.this,"删除失败",Toast.LENGTH_SHORT).show();
}
}
public void update_Click(View view){
update(name.getText().toString(),price.getText().toString(),number.getText().toString());
}
public void find_Click(View view){
find(name.getText().toString());
}
@Override
public void onClick(View v) {
}
//添加到购物车
public long insert(Sqldata sqldata){
long id = 0;
SQLiteDatabase db =null;
try {
db = helper.getWritableDatabase();
ContentValues values = new ContentValues();
values.put("name",sqldata.getName());
values.put("price",sqldata.getPrice());
values.put("number",sqldata.getNumber());
db.insert("car",null,values);
} catch (Exception e) {
e.printStackTrace();
} finally {
if (db != null){
db.close();
}
}
return id;
}
//从购物车中删除
public int delete(String name){
SQLiteDatabase db = null;
int num = 0;
try {
db = helper.getWritableDatabase();
num = db.delete("car","name = ?",new String[]{name});
} catch (Exception e) {
e.printStackTrace();
} finally {
if (db!=null){
db.close();
}
}
return num;
}
//查看购物车
public List<Sqldata> find(String name){
SQLiteDatabase db = null;
db = helper.getReadableDatabase();
MyBaseAdapter myBaseAdapter = new MyBaseAdapter(this,R.layout.item,list);
try {
Cursor cursor = db.query("car",null,null,null,null,null,null);
if (cursor.getCount()!=0){
while (cursor.moveToNext()){
Sqldata find = new Sqldata();
find.setName(cursor.getString(cursor.getColumnIndex("name")));
find.setPrice(cursor.getString(cursor.getColumnIndex("price")));
find.setNumber(cursor.getString(cursor.getColumnIndex("number")));
list.add(find);
lv.setAdapter(myBaseAdapter);
}
}
cursor.close();
} catch (Exception e) {
e.printStackTrace();
} finally {
if (db != null){
db.close();
}
}
return list;
}
//对购物车进行修改
public int update(String name,String price,String number){
SQLiteDatabase db = null;
int num = 0;
try {
db = helper.getWritableDatabase();
ContentValues values = new ContentValues();
values.put("price",price);
values.put("number",number);
num = db.update("car",values,"name = ?",new String[]{name});
} catch (Exception e) {
e.printStackTrace();
} finally {
if (db!=null){
db.close();
}
}
return num;
}
class MyBaseAdapter extends BaseAdapter {
public MyBaseAdapter(MainActivity mainActivity, int list_item, List<Sqldata> show) {
}
@Override
public int getCount() {
return list.size();
}
@Override
public Object getItem(int position) {
return null;
}
@Override
public long getItemId(int position) {
return position;
}
package com.example.myapplication;
import android.content.Context;
import android.database.sqlite.SQLiteDatabase;
import android.database.sqlite.SQLiteOpenHelper;
import androidx.annotation.Nullable;
public class MyHelper extends SQLiteOpenHelper {
public MyHelper(@Nullable Context context) {
super(context, "car.db", null, 1);
}
@Override
public void onCreate(SQLiteDatabase db) {
db.execSQL("create table car(_id integer primary key autoincrement,name varchar(50),price varchar(50),number varchar(50))");
}
@Override
public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
}
}
package com.example.myapplication;
import androidx.appcompat.app.AppCompatActivity;
import android.content.Intent;
import android.os.Bundle;
import android.widget.TextView;
import android.widget.Toast;
public class SecondActivity extends AppCompatActivity {
Intent intent = new Intent();
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_second);
intent=getIntent();
String n = intent.getStringExtra("name");
String u = intent.getStringExtra("number");
Toast.makeText(SecondActivity.this,"数据已传送，姓名："+n+"电话号码："+u,Toast.LENGTH_SHORT).show();
}
}
package com.example.myapplication;
public class Sqldata {
private int id;
private String name,price,number;
public Sqldata() {
}
public Sqldata(int id, String name, String price, String number) {
this.id = id;
this.name = name;
this.price = price;
this.number = number;
}
public Sqldata(String name, String price, String number) {
this.name = name;
this.price = price;
this.number = number;
}
public int getId() {
return id;
}
public void setId(int id) {
this.id = id;
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public String getPrice() {
return price;
}
public void setPrice(String price) {
this.price = price;
}
public String getNumber() {
return number;
}
public void setNumber(String number) {
this.number = number;
}
}
@Override
public View getView(int position, View convertView, ViewGroup parent) {
View view = View.inflate(MainActivity.this,R.layout.item,null);
TextView tname = (TextView)view.findViewById(R.id.t_name);
TextView tprice = (TextView)view.findViewById(R.id.t_price);
TextView tnumber = (TextView)view.findViewById(R.id.t_number);
tname.setText(list.get(position).getName());
tprice.setText(list.get(position).getPrice());
tnumber.setText(list.get(position).getNumber());
return view;
}
}
}
